You can't get all of the spells until NG+ or ++. There are ways to get them all offline, especially for those really grindy ones like the Blood Covenant Pyromancy and the Blue Sentinel Miracle, but you'll need to go to NG++ to do so.

I hope it's alright to post a video I made in the Dark Souls 2 thread. It's relevant, I assure you.

I made an awesome Dark Souls 2 gameplay video. It has tons of comedy and a lots of other interesting odds and ends. THIS IS NOT A LET'S PLAY! I would not waste your time by asking you to just watch me play games. Enjoy! ^_^

You're not going to be able to equip much on Sorcerer for a while. Unless they patched it, Sorcerer is a bit difficult from the beginning and middle of the game because bosses have extremely high magic defense. High as in "your pathetic melee weapon swings will do more per swing than your spells." I'd personally not focus on Attunement too early on. Upgrade your wand when you can, too.

You'll get some really basic additional spells from the Merchant in the forest, IIRC. You get more Miracles from the woman after the boss in the Tower of Flame. You'll find a devoted spell Merchant a tiny bit before the boss in No-Man's Wharf.

I'll do the exploration blind but if there's an item that needs to be used a certain way or in a certain place... etc... I'd like to know. I'll probably do new game + but I'd like to not mess up by mishandling items.